St Gwynnog Parish Church was recorded in the Montgomeryshire Inventory (1911) as having being restored to preserve original features. It now "consists of the original nave, of which the south wall was cased externally, and to which a chancel, western tower, buttressed and battlemented south porch and north vestry, were added in 1857" Thomas, Hist.Dioc. St Asaph 1908, i ,507).

Further alterations were made in 1866, and again in 1877. The roof of the fifteenth century, is the open church roof with cusped panels common to the county. The east window, originally a plain lancet, was filled with stained glass representing the patron saint, and bore the inscription: 'Santus Guinocus cujus anime propicietur Deus'.

A new window has replaced the old, and some remains of the original glass have been inserted into one of the lights on the north side. A good example of the royal arms is fixed to the north wall. The bier is dated 1759. The church was visited by the RCAHMW on 6 September 1909.

The building is listed grade II for its fine Medieval roof, which is unusual and possibly unique in Wales, nineteenth century poker-work panelling, and the wall memorials which link the church with Aberhafesp Hall.

Claire Parry, RCAHMW, 9 August 2011.

Source: Inventory of the Ancient Monuments in Wales and Monmouth I - County of Montgomery , Royal Commission on the Ancient and Historical Monuments of Wales , 1911
Cadw Record 18185